Look, men are the worst. This is no secret. It's been clear for several centuries running that a particular gender causes a lot more trouble on this planet than the other. And if all the caveman dopiness and aggression weren't enough, men are also hugely annoying when they get sick. Everyone knows this.

The term man flu is the emerging designation for this phenomenon, in which men seem to suffer disproportionate symptoms when they get the sniffles. The phrase has even made it into the Oxford English Dictionary, where man flu is defined as “a cold or similar minor ailment as experienced by a man who is regarded as exaggerating the severity of the symptoms.”

Interestingly, medical science itself weighed in on the subject this week with new research out of Canada that suggests men may actually have a legitimate complaint.

In other words, man flu may be real.

According to a research study published in The BMJ, the scientific publication formerly known as the British Medical Journal, evidence suggests that men may actually get sicker than women when it comes to influenza, respiratory infections, and the common cold.

Dr. Kyle Sue of the Memorial University of Newfoundland conducted the research, in which he analyzed and collated all the relevant medical data he could find on gender differences in severity of cold and flu symptoms. His conclusions suggest that there may indeed be an evolutionary basis to the phenomenon of man flu.

Piecing together data from various historical studies, Dr. Sue found that adult men have a higher risk of hospital admission and higher rates of flu-related deaths compared with women in the same age groups.

Men also are more susceptible to complications from acute respiratory diseases and tend to suffer from more viral illnesses. When considered together, the data support previous studies that suggest that men generally have a less robust immune system than women.

“Some of the evidence looks at how male and female immune systems are affected by hormones when faced with common viral respiratory infections,” Sue told Seeker via email. “The higher the testosterone levels, the worse the immune response; the higher the estrogen level, the stronger the immune response.”

Further analysis of the data revealed that this difference disappears at menopause, or if the female's ovaries are removed.

“Therefore, it appears that testosterone may suppress the immune system, while estrogen may enhance it,” Sue said.

“The concept of man flu, as commonly defined, is potentially unjust,” he writes in the article's summary conclusion. “Men may not be exaggerating symptoms but have weaker immune responses to viral respiratory viruses, leading to greater morbidity and mortality than seen in women.”

The publication of Sue's findings in The BMJ represents the final stage in a research project with rather humble beginnings.

“This all started as a part of my master's degree program,” Sue said. “I was told I needed to make a two-minute presentation to my classmates on any topic of interest. It just so happened that I had had the flu the week prior, and was still recovering from it — so the topic of man flu seemed pertinent and possibly entertaining.”

Sue said that publication of his research in the latest edition of The BMJ was deliberate.

“The BMJ Christmas edition is meant to be a lighthearted or humorous look at serious research,” Sue said. “All the evidence I present is real, and it's all peer reviewed, but some of my comments and suggestions were tongue-in-cheek to try to elicit a few laughs by making use of common stereotypes.”

Sue has already received a gratifying amount of feedback from men and women alike.

“Men were more likely to call me their hero,” he offered. “I've also received a lot of angry messages from people who think this study is misogynistic or sexist. Unfortunately, my use of stereotypes in my jokes didn't help my cause.”

Beyond the good-natured gender squabbling, Sue said the study actually has potential to make a significant impact on the medical world.

“If an immune gap does exist, does it mean we need to dose our vaccinations differently?” he asked. “What about medications? Many studies are done on men only, in order to avoid giving medications to pregnant women — can those studies be applicable to all genders, or are we wrong to do that?”

Sue said he hopes his research will bring about more rigorous studies.

“A big caveat is that there still needs to be a lot of high-quality research to determine whether this phenomenon is real,” he remarked. “My research suggests it, but certainly is not definitive.”

In any case, roughly half of the world's population owes Dr. Sue a little gratitude.

“At the very least,” he said, “if a man finds himself being criticized for exaggerating symptoms, he can point to this research to say, 'Hey, maybe this is just physiology.'”